Welcome to the forum - first post.

What is loose to make the NOISE?

Thoughts that come to mind would be more upfront with the hack and tools loose under the seat. In the back I would look under those seats and see what might be loose. In the very back there is a metal connection and spare tire hanging down under the bed, If it's not up tight that contraption could be rattling. Obviously there could be a variety of loos fasteners anywhere from frame, exhaust to suspension. Get help.

Have another kid down under the truck and at various places while you open and close the for which shakes things and causes the rattle. Report back if/when you find it.

 

Could be the cab vents. If you look between the cab and the bed of the truck (roughly 2" space) you should see a square vent with flaps. Those could be the rattle?

 

^^^^^^^^^^^what he said ...
here is a look at them :

 

Do you have a sun roof?

 

For me it was the hand brake cable rattling on bumps.

 

Never knew there were "cab vents". Another education well received.

Meantime I have trouble with all the windows closed trying to get the doors closed. Always need to crack a window or slam, slam the door. Maybe my vents don't work?

 

More wheaties cereal Captain, 10 push ups every morning, lol. Maybe they built yours to VW Bug specs, airtight. If you lived up here I might say it was due to the cold and everythings a bit stiff, about -10F, but that isn't the case.

 

I had Borla dual cat back exhaust on my last hemi Ram that would do that when I slammed the door. Exhaust would move just enough to hit rear sway bar end links. I c-clamped some high temp silicone hose at the contact points... Could be your issue. Grab each exhaust pipe and wiggle.

 

Sorry for the late response but I found where the noise was coming from, the metal plate on the fuel tank is loose For some reason

 

So all our ideas were poo?

At least you gaunt it and reported back. Good.